Microfluidic devices provide miniaturized environments with fluid-carrying channels that enable the control and manipulation of very small fluid sample volumes that can range, for example, from a few microliters to a few femtoliters (10−6-10−15 liter). Such devices are used, for example, in medical diagnostics, DNA forensics, and “lab-on-a-chip” chemical analyzers, and they can be fabricated using common microfabrication techniques such as photolithography.
Valves in fluidic systems are used to minimize or eliminate the flow of fluid in a specified direction. Valves in microfluidic systems often require specific materials that have limited material compatibility, and that may be expensive and/or difficult to manufacture. Valves in microfluidic systems often include moving parts, which reduces their reliability.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.